Hi! We have Exchnage 2003 Server on a Windows 2003 domain. At the beginning there was no problem with users who access their mailboxes by using Outlook 2003. But now, we have problem with existing users and new users so that they cannot open their mailboxes. There is always the following error message: "The name could not be resolved. The name could not be matched to a name in the address list. " We have checked all what Mocrosoft article describes (http://support.microsoft.com/default.aspx?scid=kb;en-us;297801) and could not find any configuration problem. How can we fix and solve problem. Please HELP!!! Best Regards Mustafa